The purpose of this contract is to establish a repository with initial capacity of 2000 unique chemicals and final capacity of 4000 unique chemicals for toxicity screening in the National Toxicology Program. This contract provides a mechanism whereby approximately 350 test chemicals per year can be located, procured, analyzed for physical properties, stored and distributed in a manner which guarantees their safe handling, chemical integrity and maintains confidentiality of identity when necessary. The repository receives a listing of chemicals which are to be tested either blind or as knowns by laboratories under contract. Concurrently with location and acquisition of these chemicals, the repository searches through on-line computer data bases to produce chemical specific handling documents both for day-to-day safe handling of the compounds as well as for emergency situations. The repository also determines the physical properties of those chemicals for which flash point, density, and vapor pressure information is unavailable in the literature. Tracking and monitoring of repository functions are accomplished by a computerized database management system. This system generates randomized codes for the various aliquots which are to be tested blind and then produces a file containing the chemical, physical and toxicological properties for each repository aliquots. The compounds are doubly contained and shipped according to DOT regulations by the most appropriate, safest and expedient possible route to the testing laboratory.